Chris Rodda on Barton's claim, picked up by Beck here (Update: and here).
One paragraph of Rodda's I want to focus on:
On Beck's show, Barton also incorporated his other lie about this letter, claiming that this was the letter that magically reunited Jefferson and Adams, who had been on the outs since Jefferson got elected president in 1800. Why does Barton do this? Because it allows him to combine two completely unrelated parts of Adams's letter into a claim that it was really God, working through his "prophet" Benjamin Rush, who restored the friendship between Adams and Jefferson.
This kind of sentiment might speak to Mormons, like Glenn Beck. But, traditional "orthodox" Christianity has no authentic position on whose side God was on during the American Founding. The outcome doesn't prove anything. Yes, according to orthodox Christian belief, God wills all outcomes, the good and the bad, Stalin, Hilter and Mao, along with America.
One could try to reason the God of the Bible would be on the more "Christian" or "Judeo-Christian" side (i.e., God would favor the Christian West verses the Godless Communists). But the American Founding involved two "Christian" sides fighting one another. And there's really no settled answer as to which side was more "biblical." There were "orthodox" and nominal, deistic and unitarian minded "Christians" on both sides. Whether America even had the "biblical" permission to do what it did on a Romans 13 basis has been hotly disputed by Christians of good faith on both sides (no need to rehash that here).
And so I've heard that many contemporary evangelicals and "orthodox" Christians of non-American descent are utterly puzzled by the attempts of certain American evangelicals and other "orthodox Christians" to seemingly incorporate the historical events of the American Founding into orthodox Christian theology.
The context of the letter, in addition to Barton's inadequacies that Ms. Rodda outlined, doesn't bode well for orthodox Christians who wish to view the founding as "godly." We have, "prophets," supposedly, John Adams, Thomas Jefferson and Benjamin Rush? Adams and Jefferson, especially at this point in their lives, bitterly rejected and mocked the Trinity and cognate orthodox doctrines. And Rush, though a Trinitarian, was a liberal Universalist who believed everyone would be saved eventually.
Yet, Mormonism, because of when and where it was founded, unlike orthodox Christianity, does teach the American Founding as some kind of divinely inspired event, and the Founding Fathers as quasi-prophets. And the unitarianism of Jefferson and Adams and universalism of Rush is no big deal to the non-orthodox Trinitarian Mormons.
In short, with all of this Glenn Beck stuff, Barton may be doing Mormonism a favor, but he does no favors for the orthodox Christianity in which he purports to believe.